prefix date and time output

[Alisher-Nabiev]

hi, i am trying to output my index like this :

output {
  elasticsearch {
    host => 0.0.0.0
    port => 9200
    bulk_limit => 1000
    bulk_timeout => 100
    index_prefix => "netflow-%{+YYYY-MM-dd.HH}"
    data_type => netflow
  }
}

but i don't receive any index in the elastic.

it works only when i put only the name "netflow"
index_prefix => netflow

[Alisher-Nabiev]

a